Phosphate additives for hydrocarbon compositions



fates atent Patented Nov. 28, 1961 3,010,903 PHOSPHATE ADDITIVES FORHYDROCARBON COMPOSITIONS John V. Clarke, Jr., Cranford, NJ., John O.Smith, Jr., Swampscott, Mass., and John F. Knnc, .l'r., Union, N.J.,assignors to Esso Research and Engineering Company, a corporation ofDelaware No Drawing. Filed Nov. 1, 1957, Ser. No. 693,817 10 Claims.(Cl. 25249.9)

This invention relates to alkylpolyoxyalkylene esters of phosphoric acidwhich are useful as additives to petroleum hydrocarbon materials. Theinvention also relates to liquid petroleum hydrocarbon compositionscontaining said esters, which compositions may also contain minoramounts of an alkyl primary amine and/or a partial ester of apolyhydroxy alcohol.

Alkylpolyoxyalkylene monoand diesters of phosphoric acid have been foundto be outstanding additives for normally liquid petroleum hydrocarboncompositions. However, they have only a limited solubility in the highermolecular weight hydrocarbon materials, such as heating oils andlubricating oils. It has been further found that by the addition ofminor amounts of an alkyl primary amine and/or a partial ester of apolyhydric alcohol and a fatty acid, that the solubility of thephosphoric acid ester in the heavier hydrocarbons is greatly increased,so that it may be used in larger and more effective quantities.

The alkylpolyoxyalkylene monoand diesters of phosphoric acid which maybe used in the invention have the following general formulas:

R[OR']..0 011 HO OH wherein R represents an alkyl group containing 2 to13, eg 4 to 10 carbon atoms; R represents a divalent aliphatichydrocarbon radical having 2 to 8, e.g. 2 to 4 carbon atoms and n isabout 8 to 18. Also included are materials having different oxyalkylenegroups in the same polymeric chain, e.g. oxyethylene and oxypropylenegroups.

Specific examples of such materials will include:

and

Materials of the above type are readily prepared by reacting P 0 with anether of a polyglycol. In these preparations it is generally desirableto slowly add the P 0 to the polyglycol monoether with rapid stirring.After the desired amount of P 0 is added, the mixture may then be heatedto temperatures of about 300 to 400 F. for about 1 to 5 hours,preferably while bubbling nitrogen through the reaction mixture in orderto provide agitation and to prevent oxidation.

The amine materials which are used as solubilizing agents for thephosphoric acid ester include tertiary alkyl primary amines of thegeneral formula:

wherein R, R and R" are straight or branched chain alkyl radicals of 1to 18 carbon atoms; the total number of carbon atoms in the moleculebeing about 12 to 24. These amines can be prepared from tertiaryolefins, eg the various polymers of propylene and isobutene; copolymersof propylene and isobutene; copolymers of isobutene and butenes orpentenes; etc. Such polymers and copolymers are well known syntheticolefins in the petroleum industry. However, in such polymerizations,various isomerizations and migrations may occur such that a mixture ofolefins are produced. Thus, a tertiary alkyl primary amine prepared fromtri-isobutene may contain tertiary alkyl primary amines of 13, 14 and/or15 carbon atoms as well as the predominant one of 12 carbon atoms.Similarly, when making a tertiary alkyl primary amine of 18 carbon atomsfrom hexapropylene, a polymer of propylene, one may obtain a mixture oftertiary alkyl primary amines having predominantly 18 carbon atoms permole cule with minor amounts of homologous molecules with 19, 20, 21,22, 23 and/or 24 carbon atoms. Such a mixture is conveniently designatedt-C H NH Specific examples of tertiary alkyl primary amines which may beused include the following:

3-amino-3,S,8-trimethyl-nonane S-amino-S,13-dimethyl-hexadecane3-amino-3,5,7,9,12-pentamethyl-tridecane 4-amino-2,4,6,8,IO-pentamethyl-tridecane 2-amino-2,4,4,6,6,8,8-heptamethyl-nonane6-amino2,2,4,4,6,8,8-heptamethyl-nonane The partial esters of thepolyhydroxy alcohol useful for solubilizing the phosphate ester includeC to C fatty acid partial esters of aliphatic polyhydric alcohols havingabout 3 to 8 carbon atoms, and about 3 to 6 hydroxy groups per molecule.Preferred materials are the monoand diesters of C to C alcohols having 3to 6 hydroxyl groups which are prepared from C to C fatty acids. Theabove type of partial esters include the partial esters of themono-dehydrated aliphatic polyhydric alcohols which are described in US.Patent 2,434,490 as well as partial esters of non-dehydrated aliphaticpolyhydric alcohols. Specific examples of these partial esters include:sorbitan monooleate, glyceryl monooleate, pentaerythritol monooleate,the dioleates of sorbitan, mannitan, pentaerythritol and relatedpolyhydric alcohols, the corresponding partial stearic,-laur1'c, andpalmitic acid esters of these alcohols, and partial esters of thesealcohols made from mixtures of these fatty acids. Preferred materialsare the monooleates of sorbitan and pentaerythritol.

The norm-ally liquid petroleum hydrocarbon materials, with which thephosphoric acid ester may be used as an additive, may range fromgasoline through heavy lubricating oil. Such hydrocarbon materials willtherefore include aviation, marine and automotive or motor gasolines;

IP1, JP-4 and JP5 fuels; domestic aviation turbo fuels, such as marine,stationary and automotive diesel fuels; and industrial fuel oils andlubricating oils.

The liquid engine fuels, i.e. gasolines and diesel fuels, will compriseat least 95 wt. percent of a mixture of hydrocarbons with a boilingrange of about 75 F. to 750 F., and will have a viscosity of about 0.264to 26.4 centistokes at 77 F. This includes motor gasolines havingboiling ranges of 75 F. to 540 F. and viscosities of 0.264 to 1.0centistoke at 100 F., aviation turbo fuels whose volatility is such thatthe end point does not exceed 572 F. and whose viscosity is between 0.5and 1.5 centistokes at 100 F., diesel fuels which boil between about 250F. to 750 F. and have viscosities of 1.4 to 26.4 centistokes at 100 F.The fuel oils include gas oils which are petroleum distillatesintermediate in volatility between kerosene and lubricating oil andwhich may include cracked hydrocarbon stocks. The lubricating oils willinclude those oils of about 30 to 350 SUS viscosity at 210 F.

The compositions of the invention will therefore comprise a normallyliquid petroleum hydrocarbon and about .005 to 5.0, e.g. .01 to 2.5 wt.percent, of the phosphoric acid ester. In hydrocarbon oils, such as fueloils and lubricating oils, where the phosphate normally has only alimited solubility, then the composition may also contain about 50 to300 wt. percent, e.g. 75 to 200 wt. percent, based on the weight of thephosphoric acid ester, of a solubilizing agent. The solubilizing agentin turn may consist entirely of the tertiary alkyl primary amine or ofthe partial ester of a polyhydroxy alcohol. However, best results aregenerally obtained by using a blend consisting of about 30 to 80 wt.percent of the tertiary alkyl primary amine and about 70 to 20 wt.percent of the partial ester. Not only does the amine and/or partialester increase the solubility of the phosphate in the oil, but they alsoenhance its effectiveness as well as being useful additives in their ownright.

Various other conventional additives may also be added to thecompositions of the invention. additives include: detergents, viscosityindex improvers, corrosion inhibitors, pour depressants, dyes, and thelike.

The invention will be further understood by the following examples:

EXAMPLE I Preparation of the phosphate additive A mixed phosphateconsisting primarily of n-butyl (polyoxypropyleneh dihydrogen phosphatewith a minor amount of n butyl (polyoxypropyleneh monohydrogen phosphatewas prepared as follows:

4 wt. percent of P was slowly added with rapid stirring to 96 wt.percent of an ether alcohol of the formula: n-CdhlOCBz-filfl -0H UC{HQ(OCHY CH -O-'P:O (551mm. Wt.)

CH2 i1 HO OH with a minor amount of the monohydrogen phosphate:

0.5 wt. percent and 4.0 wt. percent of the above reaction product wererespectively mixed with a 5W-20 lubricating base oil. This base oil wasa neutral, ex-

tracted Mid-Continent mineral lubricating oil containing a minor amountof polymethacrylate as a viscosity index improver. The mixtures werethen tested in the 4-ball EP. test for load-carrying ability and theresults of these tests are summarized in the following table:

TABLE I Percent t-Ball Phos- E. P. Test t. Percent Additive Added toBase Oil phorus (load in Oil carried in kg.) None 0 50 0 5 wt. percent 10t solution containing 50 wt.

percent n-butyltoxypropylene)n phosphate. (12 85 4.0 wt. percent 1 ofsolution containing 50 wt.

percent nbutyl (oxypropyleuchz phosphatmI 1 Maximum quantity that couldbe put in solution. 1. Additive partly dissolved and partly suspended.

As seen from the above table, the additive material (product of ExampleI) which consisted of a 5 0 wt. percent solution of n-butyl(oxypropyleneh mono and dihydrogen phosphate in n-butyl ether ofpolypropylene glycol was very effective as a load-carrying agent.Actually, this improvement was due solely to the phosphate, the etherglycol material being inert. It is also to be noted that the additivematerial was soluble in the oil only to the extent of 0.5 Wt. percent,although larger quantities can be suspended to impart even higherloadcarrying ability to the oil.

In order to increase the amount of phosphate which can be dissolved inthe oil and thereby increase its effectiveness, the amine and/ or thepartial ester of a polyhydric alcohol can be used as solubilizingagents. This is illustrated by the following examples:

Examples of such EXAMPLE II with 90 wt. percent of a neutral minerallubricating oil wt. percent of Primene IM-T.

wt. percent of Primene having a viscosity of 43 SUS at 210 F. A clearsolution resulted which did not separate upon standing.

B. An additive mixture was prepared by mixing 50 wt. percent of then-butyl polypropoxy material with 50 10 wt. percent of this mixture whenadded to 90 wt. percent of mineral oil (same as in A) resulted in asolution having a slight haze.

C. Example IIB was repeated except that 50 wt. percent of sorbitanmonooleate was used in place of the 50 I M-T. 10 wt. percent of thisadditive mixture, when added to the 90 wt. percent mineral oil resultedin a solution having a distinct haze.

As seen from above, the mixture of the amine and phosphate material,when added to the mineral oil (Example II-B) resulted in a slight haze.A more distinct Thus, while either the amine load-carrying ability.

haze resulted when the sorbitan monooleate was used with the phosphateinstead of the amine (Example II-C). However, by using both the amineand the sorbitan monooleate (Example II-A) a clear solution resulted. orthe fatty acid partial ester of a polyhydroxy alcohol will solubilizethe phosphate, the best results are obtained by using a mixture of suchsolubilizing materials.

The composition of Example lI-A was tested for The results of thesetests are summarized in the following table, along with the results ofthe similar tests run on the base oil per se and on the base oilcontaining 5 wt. percent of the phosphate material, the bulk of whichwas in suspension due to its limited solubility.

TABLE II minutes, and then allowed to stand for one hour. The volume ofthe oil layer, the water layer and the emulsion Run C I Load Car- LoadCarlayer was then measured.

ompfsmm' "1 g The composition was also tested for rusting character-E.P. Test Machine 5 istics by suspending polished steel strips in atwo-phase system of the fuel oil composition and water, and then $g()7%lgiineral 11 (43 $05. at 210: a). 42 a2 bubbling air through thesystem. The steam emulsion g fiig g fi figfgggg g 95 127 number of thefuel oil composition was also determined 3 C 3 ten-bully](oxypropylenchzaccording to -ASTM Dl57-5 l-T test method.

90% Mineral'ofl (43 0 R) 88 146 Results of the preceding tests are givenin Table IV, 52 05 solgtitonl containing so wt. along with comparabledata on the uninhibited base g g' zgi g ifgggf oil, and a commercialfuel oil composition. oleate, 2.5% mixture of Cis-u t.-nlkyl primaryamines. TABLE IV As seen from Table II, the addition of 5 wt. percent 15nersheigmuision RuStTest of the phosphate material (about 0.5 wt.percent of Test Steam which was in solution, the remainder beingsuspended in the oil) materially increased the load-carrying ability g{fi l' Eater N0 of the oil (compare runs 1 and 2). However, the sus- $23ayer pended portion of the phosphate will quickly settle. Run

3, however, represents a stable solution of the phosphate 1. Base Oil 42a2 7 trace" heavy. 19

and which had substantially the same loadcarrying i pg f 32 20 27heavyability as run 2, showing a slightly better result in the 3.Zf?asedll+.0;l% Son 42 a9 0 none trace. 33

itan n jfzljllmealehine and being slightly less effective in thefiglfiggigi In addition to its load-carrying ability, the materials ofthe lHVHllOH represent valuable additives for fuel oils. polypropoxyphos- This is illustrated by the following examples:

EXAMPLE In The data in Table IV shows that the additive combina- Acomposition was prepared consisting of 0.05 wt. tion of the inventionrepresents an excel-lent fuel oil adpercent of the reaction product ofExample I which ditive giving good rust inhibition and having 'littletencontained wt. percent of n-butyl polyoxypropylene dency to emulsifywater into the oil.

phosphate in solution in an inert solvent; 0.025 wt. percent of sorbitanmonooleate; and 0.025 wt. percent of 0 EXAMPLEV the C tertiary alkylprimary amine material (Primene JM T) i a N 2 heating This heating n wasa To demonstrate the advantage of the phosphate in a blend of equalparts by weight of a virgin gas oil and a gasoline, the followingexperiment was Parfommd2 catalytically-cracked gas oil. The compositionwas tested 40 Percent of nbutyl Polyoxypmpylene Phosfor sediment formingtendencies by heating for 16 hours Pilate Product mammal of Example wasadded to a at 210 F., followed by filtering to determine the amount highP gasoline containing 017% Sulfur This of sediment formed. The resultsof this test are reported gasolme cOmamed of 'tetraethyl lead per gallonin Table III, which follows, along with sedimentation and had anfind'pomt of about (ASTM D436)- values for the base fuel oil and blendsof the base fuel The inhibited l was tested. in a Single cylin oil withthe phosphate material per se and with the der f f spark-lgmtcdeasol-meengine equi'PPQd with solubilizing agents per se. a radloacuvc P P TABLEIn Each test consisted of a series of five 5-minute runs with a 30minute shutdown between each run. During the shutdown, cooling water wasrun through the jacket,

Sediment o it. Percent Additive added to Heating on (mg/100 bflngmg (helaCkBl Watfldmt temperature to 60 R Each 1111-) five minute runtherefore began at 60 F. No cooling N was used during the five minuterun and the water-out e 4 m ra-turc was allowed to reach its own fivfil,Which 'liiZ piiii?e" il 9.ill.ffiilii'ffffi.FTKTTK'Q 10 w s i wil F. atthe e of the Two series of fi' ifg f 2 55 runs were made each day, one areference run on refer-..

115% of a Somali (3iii iaiiiiizaiygaiiyiaiioi;his; ence fuel and theother a test run on reference g i gfli ggh gg monooleamv WWW 1 fuel plusthe additive. Before either the reference or test run, the engine wasrun for fi-ve minutes on the fuel to be tested in order to wet-down theengine. These is gzz zg g fiiii g gg'i ig iz gg gi f gg gzxgz; 0 fiveminute wet-down runs were at a higher temperature and amine was moreeffective in reducing the formation th-an the genes of cychc five mmutcmnS-whlch con- Of sediment than would havc been expected fiom thestituted the reference or test runs. Following the wetindividual died ofthe components down, there was a 30 minute shutdown after which thereference or test run began. Each run was made on a EXAMPLE IV 5 freshcharge of summer grade mineral oil containing no A Composition wasprcpared Similar to that f Examadditives. A load of 1.6 BKW. and a speedof 1800 ple III, except that a different proportion of the additives r-P- were maintained throughout {b6 P was used. At the end of each run,the oil charge was drained Th above composition was tested f l if i anddip counted with a scintillation counter in order to ability in amodified Hershel emulsion test, which was determine the amount of ironwhich had bean Worn Off carried out as follows: 40 ml. of the fuel oilcomposition thfl radioactive P Compression Ting into the crankcase undertest was mixed with 40 ml. of distilled water and lube then placed in aconstant temperature bath until the mix- Each wear measurement wasrepeated at least six times ture reached 77 F. The mixture was thenstirred with a and the average results are given below, along withcompropeller type mixer rotating at 1500 rpm. for five parable wear dataon the uninhibited gasoline.

Que

0.1% n-butyloixyprop. rich: Dlto spn if dient);

.Although, fr convenience, the phosphate material used in the precedingexamples wasjin the 'form'of a solution in "rt-butyYmonoethcr ofpolypropylene glycol, similar compositions can be prepared by using apure phosphate material. Thus, the phosphate portion of the reaction p dc f E a ple r m. b: s p ted. if mtlteneez reacted polypropylene glycolmonoether l. Simple extraction and used directly.

A. A lubricating oil composition is prepared by mixing 4.0 wt. percentof n-butyl (oxypropylcne) dihydrogcn phosphate having the formula:

l nC "ll- .(OCUECHMO-l 0 y no OH with 96.0 wt. percent of a minerallubricating oil having a viscosity of 80 SUS at 210 F.

B. A fuel oil composition is prepared by mixing 1.0 wt. percent ofn-octyl (oxycthyleneh monohydrogen phosphate having the formula:

[iidn-(0 C IC ?)IE( EI' I ;O on with 99.0 wt. percent of a No. 2 fueloil of the type described in Example lll-. 3 V

C. A gasoline composition is prepared by mixing .10 wt. percent ofn-butyl (otypropyleneh dihydrogen phosphate into a motor gasoline havinga viscosity of .5 centistolze at -l00 F.

While the alkylpolyoo'a kylcne monoand dicsters ofphosphoric acidcan beused in amounts of .005 to 5.0 wt. percent in petroleum hydrocarbons.generally about .005 to 1.0 weight percent will be used ingasoiines andheating oils, while 0.5 to 5.0 wt. percent will be used in lubricatingoils.

Aspreviously-mentioned. other additives may also be used in-coriiunctionwith the alkylpoiyoxyalkylene esters of phosphoric acid to furtherenhance their effectiveness. One such additive is a copolymer consistingof 80 wt. ercent Lorol B" methacrylate and 20 wt. percent of fl-diethylam noethyl methacrylale. as descri ed in US. Patent 2.731 52. The Loro:8" refers to a technical lauryl alcohol. Thus. a kerosenecomposition'was preparedcontaining 0.0025 wt. percent of. the abovecopolymer in combination with 0.0075 wt. pereentcf a mixture of C to-Ctertiary alk-yl p imary iamines prepared from tri-isobutene and 0.01'wt. percent. of the phosphate reaction product of Example .l.-' Thiskero-.= sene -com-position was found particularly useful asa jet fuelsince the/additive combination increasedv the thermat stability of'thekerosene andreduced its deposit form% ing tendencies uponcombustion.Another useful additive-is morpholine, which can .be used in combinationwith the phosphoric acid ester'inleaded' gasolines. .The precedingare'intended to merely illustrate the use ofv other additives in combinationwith the alkylpolyoxyalkyl ene esters of phosphoric acid ofthe-invention. itbeing understood, of course; that still other additivematerials may thus be used.

' What is claimed is: l. A liquid petroleum hydrocarbon composition'comprisinga major proportion of a normally liquid .pe troleumhydrocarbon selected .fromthe group consisting of lubricating oils. andgasoline and about .005to 5.0 wt. percent of a phosphate selected fromthe group consisting of alkylpolyoxyalkylene monoand diesters ofphosphoric acid,..wher.ein said .alkfl. groups contain 2. to 13 carbonatoms, said oxyalkylene groups each contain 2 to 8 carbonatoms, and thenumber of said oxyaikylene groupsjper ester'group is about 8 to 18.

..ls.A compositio.u .accordingtoclaim 1 wherein said. petroleumhydrocarbon is gasoline.

3. A composition accordingto claim 1 wherein said petroleum hydrocarbon.is a lubricating oil..

4. A composition aocordingto claim 1 wherein said ester of phosphoricacid isi'an n-butyl polyoxypropyicne' phosphate. 1

5. A composition accordingto claim 4, wherein said phosphate is n-butyl(oxypropylcney phosphate.

- 6. A composition of matter-consisting essentially of amajorpropoirtion offanormally liquid petroleum hydrocarbon,;about0.005.to 5.0 Wt. percent of a phosphateselected fIOl'11'.ll1C groupconsisting-of ,alkylpolyoxyalkyL ene mono and. diesters of. phosphoricacid, wherein said alleyl groups contain-21013 carbon atoms, saidoxyalkylene groups each contain 2 to-S carbon atoms, and the numbecof'said oxyalkylene groups per: ester. group is about 8 to'. 18, about '50to 300 wt. percent, based on the'weight of'saidester of phosphoric acid.of a materialselectedlfroma grouptconsisting of tertiary alkyl primaryamines containing l2 to 24 carbon atoms permolecule and; Ci 10.10 fattyacid partial esters of aiiphatiopolyhydric alcohols having about 3 to 8carbon atoms and about. 3' to 6 'hydr'oxy'groups per molecule. andmixtures thereof.-;

7. A composition according to claim 6 wherein said petroleum hydrocarbonis a fuel oil.

8! A liquidpetroleum-hydrocarbon composition comprising a majorproportion of a norm-ally liquid petroleum hydrocarbon selected from thegroup consisting of lubricating oils, and-'gasolines and about 0.05 to5.0 wt. percent of alkylpolyoxy propylene monoester of phosphoric acid,'wherein said alkyl group contains 2 to-l3 carbon atoms, and the nunr-ber of oxypropylen'e groups is about 8tol8.

9. A composition=according to'claim S, which also contains alkylmono'ether of polypropylene glycol in an amount equal-to theamountof-said mon'oester, wherein the alkyl group- 0f said monoethercorresponds to the aikyl group of saidmorroester, and the number ofpropylene oxide groups in -said-monoether corresponds to the number ofpropylene oxide groups in said monoester.

10. A method of preparing alkylpolyoxyalkylene monoand diesters ofphosphoric acid; wherein said alkyl group contains 2 to l3 carbon atoms.said oxyalkylene group contains 2 to 8 carbon atoms and the number ofsaid oxyallsylene groups per ester group is aboutfi to 18, whichcomprises reacting P 0 with in excess of 2 molar proportions ofarnonoether of a polyglycol per molar proportion of said P 0 attemperatures of about 300 to 400 F. for about I to 5 hours.

acetates Cited in the fileof this patent Ntrgo STATES A EN S .2 1 B n gt -.-----.M y-ll .1937; Volzet als July 26, 1949 Mikeska et al.; June l2 1956 2.934.500 Cantrell et al. Apr. 26, 1960 tlas Powder C0.

1. A LIQUID PETROLEUM HYDROCARRBON COMPOSITION COMPRISING A MAJORPROPORTION OF A NORMALLY LIQUID PETROLEUM HYDROCARBON SELECTED FROM THEGROUP CONSISTING OF LUBRICATING OILS, AND GASOLINE AND ABOUT .005 TO 5.0WT. PERCENT OF A PHOSPHATE SELECTED FROM THE GROUP CONSISTING OFALKYLOPOLYXYALKLENE MONO- AND DIESTERS OF PHOSPHORIC ACID, WHEREIN SAIDALKYL GROUPS CONTAIN 2 TO 13 CARBON ATOMS, AND OXYALKYLENE GROUPS EACHCONTAIN 2 TO 8 CARBON ATOMS, AND THE NUMBER OF SAID OXYALKYLENE GROUPSPER ESTER GROUP IS ABOUT 8 TO 18.